Tripping mechanism for printing-presses.



PATENTED MAR. '7, 1905.

T. G. DEXTER.

TRIPPING MEGHANISM FOR PRINTING PRESSES.

APPLICATION FILED MAR. 30,-1904.

-8 SHEETS-SHEET 1.

No. 784,479. I PATENTED MAR. 7, 1905. T. C. DEXTER.

TRIPPING MECHANISM FOR PRINTING PRESSES.

APPLICATION FILED MAR. 30, 1904.

3 SHEETS-SHEET 2.

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.1 S W 3311M flttomww No. 784,479. PATEN'TED MAR. 7, 1905.

T. G. DEXTER,

TRIPPING MECHANISM FOR PRINTING PRESSE S.

APPLICATION FILED MAR. 30, 1904.

3 SHEETS-SHEET 3.

UNITED STATES Patented March '7, 190 5.

PATENT OFFICE.

TALBOT C. DEXTER, OF PEARL RIVER, NEW YORK.

SPECIFICATION fOrming part of Letters Patent No. 784,479, dated March 7, 1905.

Application filed March 30, 1904. Serial No. 200,777.

To (117/ whom it may concern:

Be it known that I, TALBOT C. DEXTER, a citizen of the United States, resldlng at Pearl River, in the county of Rockland and State of New York, have invented certain new and useful Improvements in Tripping Mechanism for Printing-Presses, of which the following is a specification.

This invention relates to improvements in a tripping mechanism of the kind employed in prin ting-presses for throwing the impressioncylinder out of printing position and rendering inoperative the printingpress driving mechanism.

The object of the present invention is to construct an eflicient tripping mechanism which can be either automatically or manually operated and in which the strain and jar usually incident to such tripping operations will be wholly obviated.

Heretoforc in the construction and operation of trippingmechanisms of this kind much trouble has been experienced by the parts becoming disarranged, broken, or rendered inoperative. This has been due to the fact that a very powerful operating medium is employed to operate the several parts when the device is tripped. The operating medium must exert sufiicient power to rapidly shift the driving means from operative to inoperative position and simultaneously apply the tripped, the consequent result being a sudden stopping of the parts at the limit of their movement or after they have concluded their operative functions which tends to injure and ofttimes disarrange or break the parts.

One of the purposes of this invention is to construct a tripping mechanism wherein the operating medium (preferably springs) will exert but a small proportion of its operating power when the parts are in normal or in untripped position, thereby permitting the latching devices to be easily disengaged from the tripping member when the sheet-tripping mechanism operatively controls said latching devices. This is accomplished by arranging the parts so that the tripping members will be secured to the operating medium in such manner that the exerted force of said operating medium will be almost directly toward the axes of the tripping members when said members are in untripped position, thereby permitting the use of a very powerful operating medium for rapidly moving the tripping members after they have been released by the latching devices.

Another purpose of the invention is to provide means which will act asa cushion for the tripping members to take up the jar and vibration incident to the tripping operation that is, when the tripping members are released and moved by the operating medium. By placing dash-pots in proximity to the tripping members and suitably connecting the pistons of said dash-pots to the tripping members it will readily be observed that the desired cushioning effect will be obtained and a tripping mechanism produced, which will obviate the hereinbefore-noted objections now existing in the present form of tripping mechanisms. Tripping mechanisms of this kind are usually made in duplicate form and located adjacent to each other, one mechanism beingemployed to operatively control certain devices for stopping the press and the other mechanism being adapted to operately control the devices for moving the impression-cylinder into and out of printing position. Both tripping mechanisms are directly controlled by means operatively controlled by the passage of the sheets through the press.

This invention comprehends certain novel combinations and organizations of instrumentalities hereinafter more fully described and then specifically designated in the claims.

In the accompanying drawings, Figure l is an elevation showing the tripping mechanism and its operative relation with a printingpress. Fig. 2 is an enlarged view of the tripping mechanism, showing the parts in normal or unreleased position. Fig. 3 is a similar View showing the parts after they have been released and operated. Fig. 4 is a plan view of Fig. 2. Fig.5 is a detail end View of the mechanism looking to left in the other figures.

In the construction and practical application of the invention, 1 1 are the supporting side frames of an ordinary printing-press; 2, the su pporting-framework of the feeding-machine from which the sheets are fed to the press.

3 is the feed-board, and 4 the impressioncylinder, which receives the sheets from the feed-board.

A main driving-shaft 5, suitably journaled in the side frames of the press, has mounted on one end thereof fast and loose pulleys 6 and 7, which are operatively controlled by a driven belt 8. A belt-shifting device 9 is pivoted on a supporting-bracket 9 and movable laterally by means of an arm 10, connected to abell-crank 11, pivoted upon bracket 11, said bell-crank being in turn operated by a rod 12, controlled by the tripping mechan- -ism and adapted to shift the belt from the fast pulley to the loose pulley when the tripping mechanism is operated.

15 is a reciprocating bar, which is notched to engage a rock-arm 16, whereby it can be intermitten tly operated to cause the toggle-links 17 to move the impression-cylinder into and out of printing relation to the form. Pivotally supported under the free end of the reciprocating bar 15 is an arm 18, to which is attached a rod 19-, said rod being controlled by the tripping mechanism to move the reciprocating bar 15 into and out of engagement with the rock-arm 16, whereby the'impressioncylinder can be held out of printing position a definite period of time.

Part of the sheet-controlled mechanism for operatively controlling 'the tripping mechanism to release it when necessity requires is shown at 20 and is directly connected to the tripping mechanism by'a bell-crank lever 21, which when operated by the sheet-controlled mechanism will raise the rod 22 and release the tripping mechanism in a manner hereinafter morefully explained. The construction and operation of the belt-shifting mechanism, impression-cylindercontrolling mechanism, and the devices employed to operatively control the tripping mechanism are clearly shown and described in the patent to me, No. 665,072, dated January 1, 1901, for automatic controllers for printing-presses.

The tripping mechanism is constructed and arranged in the following manner: Suitably secured to the frame of the press, adjacent to the base thereof, is a U-bracket 25, in which is supported a short horizontal shaft 26, said shaft being held in position by a set-screw 26.

Independently journaled on this shaft 26 between the sides of the bracket are the two main tripping members 27 and 28., which are preferably, as here shown, segmental in formation, each having a radiallyprojecting arm 27 and 28, for purposes hereinafter more fully explained. The tripping member 27 has pivotally connected thereto, as shown at 27", the rod 12, which operatively controls the mechanism for shifting the belt when the tripping member is operated. The tripping member 28 has pivotally connected thereto near its base, as shown at 28", the rod 19, which operatively controls the mechanism for moving the impression-cylinder into and out of printing position when the said tripping member is operated.

Pivotally mounted on a stud 30, secured in an upwardly-projecting portion of the bracket 25, are two latches 31 and 32, the free ends of which are adapted to engage antifriction-rollers 33 and 34, mounted on laterallyprojecting studs 35 and 36, secured in the upper ends, respectively, of the tripping members 27 and 28. When the latches are in the position shown in Fig. 2that is, in engagement with the antifriction-rollers 33 and 34* the tripping members will be held against operation in position to be tripped. Passing transversely through and connecting the free ends of the latches is a pin 38, which is engaged between the latches by the slotted lower end of the vertical rod 22, said rod when lifted disengaging the latches from the trip ping members and allowing said tripping members to operate.

The means for actuating the tripping members when released by the latches consists of operating-rods and 41 pivoted, respectively, to the radial arms 27 and 28 of the tripping members and at a point near the axis of said tripping members, as indicated at 42 and 43. The lowerends of these operating-rods are guided in lugs 44 and 45, forming part of the bracket 25. Mounted on the rods 40 and 41 and operating the tripping members are the expansion-springs 46 and 47, the lower ends of which rest against the respective lugs 44 and 45, while the upper ends are engaged'by collars 48 and 49.

It will be noticed by referring to Fig. 2, which shows the parts in position to be tripped, that the operating-rods 40 and 41 under the influence of their springs exert a force almost directly toward the axes of the tripping members. This arrangement permits the use of very powerful springs to rapidly move the tripping members after they have been unlatched and at the same time the thrust of the springs toward the axes of the tripping members holds the springs in subjection and relieves the pressure between the engaging-studs on the tripping members and the latches, so as to allow the easy disengagement of the latches.

Formed integral with or secured to the bracket 25 adjacent to the base thereof are two horizontal cylinders 55 and 56. \Vithin the cylinder 55 rides a plunger 57, Fig. at, the outer end of which is connected through a link (not shown) with the lower end of the tripping member 27 or the member which operatively controls the belt-shifting mechanism. Riding within the cylinder 56 is a plunger 59, the outer end of which has pivoted thereto a link 60, said link being in turn pivoted to the lower end of the tripping member 28 or the member which operatively controls the mechanism for shifting the impressioncylinder into and outof printing position. The connection between plunger 57 and tripping member 27 is not shown, but will be understood, since it is the same as the connection between plunger 59 and tripping member 28, as shown in Fig. 3. Each cylinder has inserted in the end thereof a petcock, as shown at 63 and 64, for regulating the quantity of air to be emitted from the cylinders by the action of the plunger, thereby controlling the rapidity of movement of the plungers.

By constructing and arranging the cylinders as above described and operatively connecting their plungers to the tripping members dash-pots are formed which will act to cushion the tripping members when they are released and take away all strain and jar that would of necessity occur should the said tripping members be suddenly stopped or permitted to linish their movement unrestrained. Thus it will be seen that powerful springs can be employed to impel the tripping members and rapidly and effectually operate the mechanisms controlling the impressioncylinder and the press-driving means. it is deemed advisable to have the two tripping members 27 and 28 move independently of each other owing to the fact that it is desirable to throw the impression-cylinder out of printing position as quickly as possible when a mishap has occurred in the feeding or transit of a sheet. The impression cylinder tripping member having but a small load to shift will move rapidly and in advance of the tripping member controlling the belt-shifting mechanism, the latter tripping member having to exert sufficient force to shift the driving-belt from the fast to the loose pulley.

It is necessary to provide means for manually releasing the tripping members, so that the operator can at all times control the operation of the press. This is accomplished by having a short rock-shaft 7O suitably journaled in a hub 71, forming part of the bracket 25. Secured to this rock-shaft directly under the latches 31 and 32 are rock-arms 73, which are adapted to engage the under faces of the said latches when the tripping members are held in position to be tripped, as shown in Fig. 2. In order not to move or disturb the sheet-controlled mechanism for automatically releasing the tripping members when the manual means are operated, the lower end of the rod 22 is slotted to allow free movei'nent of the pin 38, as shown atia". The rock-shaft has attached to its inner end a dependent rock-arm 75, to the lower end of which is pivoted a rod 76, said rod in turn being connected to a hand-lever 77, suitably pivoted, as shown at 78, to the side frame of the press or feeder in a position best suited for convenience of operation.

The tripping members are returned to latched position after having been operated by means of vertical rods and 81, pivoted, respectively, to the radial arms 27 and 28' of the tripping members. These rods extend up through the operators platform 83 and are provided with foot-plates 8%, by which the operator can readily operate them when be desires to reset the tripping members.

The. tripping members are operatively controlled and in turn control the operation of the press in the following manner: \Vhen the sheet in transit for any reason whatsoever rocks the bell-crank lever 21 through the medium of the mechanism shown at 20, the vertical rod 22, which is directly connected to the latches 31 and 32 will be raised, thereby simultaneously freeing said latches from engagement with their respective tripping members. When the tripping members are released they will under the influence of their opcrating-springs 46 and at? be instantly rotated on their axes and operate the tripping mechanisms connccted thereto. The tripping member 28 or the one which operates to shi ft the impression-cylinder will when released by its latch rapidly rotate on its axis and pull the rod 19 in the direction of the arrow, as shown in Fig. 1. The movement of this rod 19 will rock the arm 18 and cause said arm to lift the reciprocating bar 15, so that it will be disengaged from the oscillating arm and the toggle-lin ks allowed to remain in their normal position or the position in which the impression-0y]inder is held out of printing relation with the form. As the tripping member 28 accomplishes the above result the plunger 59, secured to the lower end of said member, will be driven into the cylinder 56, cushioning said member and gradually arresting its rotation. The tripping member 27 or the one which operates the belt-shifting mechanism will when released by the latch rotate on its axis, thereby pulling down the rod 12, which is pivoted thereto, in turn rocking the bell-crank lever 11, which controls, through the arm 10, the belt-shifting device 9. This tripping member also has the plunger 57 connected with the lower end thereof, which is driven into the cylinder 55 and acts to cushion and arrest the tripping member when said tripping member is released or moved to tripped position. The tripping members are restored to latched positionby depressing the rods 80 and 81 suliiciently far to allow the latches 31 and 32 to engage the antifriction-rollers on the upper ends of said tripping members, in which position they will remain until again tripped. Of course it should be understood that the tripping members need not necessarily control the stopping of the press and the shifting of the impression-cylinder by mechanical means, but may be operatively connected to electrical devices for the same control of the press.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, is

1. Controlling mechanism for machines designed to operate upon sheets, having in combination a rotary throw-out member for said machine, an actuating device connected eccentrically with said rotary throwout member, a cushioning-cylinder, a piston working in said cylinder and connected eccentrically With said rotary throw-out member, and automatically-controlled latching means normally locking said rotary throw-out member against movement, substantially as set forth.

2. Controlling mechanism for machines designed to operate upon sheets, having in combination a rotary throw-out member for said machine, an expansion-spring device eccentrically connected with said rotary throw-out member for actuating it, a cushioning-cylinder,-a piston working in said cylinder and connected eccentrically with said rotary throw-out member, and an automatically-con-' trolled latch normally engaging and locking said rotary throw-out member, substantially as set forth. I

3. Controlling mechanism for machines designed to operate upon sheets, having in combination a rotary throw-out member for said machine, an expansion-spring device connected eccentrically with said rotary throwout member at a point close to its center of rotation, a cushioning-cylinder rigidly mounted independently of said throw-out member, a piston operating in said cylinder, a connection between said piston and said throw-out member, the connections of the actuatingspring device and the retarding-piston being upon opposite sides of the center of rotation of said throw-out member, and normally active restraining means engaging said throwout member and holding it at rest, substantially as set forth.

TALBOT C. DEXTER.

Witnesses J; GREEN, WM. E. KNIGHT. 

